One of the major characters is Maria, though the reader doesn't learn that it is she until the epilogue. This is because the narrator, remaining anonymous, allows the reader to imagine themselves in this position. It also serves to set the reader up for the emotional shock of learning her identity. She's referred to, in much of the book, as Chick's daughter. This allows for the theme (reclamation of love) to come through loud and clear.
Chick is the central charcter and it is his life that the story revolves around. His memories of his past and his near death encounter shape his sotry. We see his deserpation to have his father's love and how they define him and motivate his choices. We see his relationship with his mother as strained. What this serves to do is to not only offer insight into Chick's mental and emotional state, but to offer another theme: children never fully understand or know the lives of their parents, nor can they fully understand how significant their influence is on their own lives.